Some properties of two forms of alpha-glucosidase from Saccharomyces cerevisiae-Ii
Krakenaĭte, R.P.; Glemzha, A.A.
Biokhimiia 48(1): 62-68
1983
ISSN/ISBN: 0320-9725 PMID: 6338938 Document Number: 208091
The amino acid composition of two forms of alpha-glucosidase from the yeast Saccharomyces cerevisiae-II was established and the values of Km, V, kcat and kcat/Km for maltose, maltotriose and p-nitrophenyl-alpha-D-glucopyranoside (PNPG) were determined. PNPG possessed a much higher affinity for the enzyme as compared to sucrose, maltose and maltotriose. The value of V decreased in the following order: PNPG greater than sucrose greater than maltose greater than greater than maltotriose. No differences between the kinetic parameters of individual forms of alpha-glucosidase were observed. Glucose, fructose and methyl-alpha-glucoside act as competitive inhibitors. The two forms of alpha-glucosidase under study have an identical pH optimum and thermal stability.